1. Field of the Invention
The present invention relates to molten steel pouring methods and apparatus, in particular (but not solely) for supplying continuous casting moulds.
2. Description of the Prior Art
Pouring apparatus constituted by refractory nozzles fixed to the base plate of the liquid steel distribution tundishes provided in continuous casting plants is known. The utility of the nozzles, whose number corresponds to that of the casting lines, lies in the determination of the casting speed which is fixed by their diameter; this speed may nevertheless be slightly adjusted by modifying the steel level in the distribution tundishes.
It is known that the use of the continuous casting method contributes to decreasing the final cost price of iron and steel plants. For this purpose, the design of the majority of plants enables sequential casting in which the steel ladles are changed using a rotating turret and the distribution tundishes may possibly be changed "on line" without having to reset the machine according to the "dummy billet" method.
Sequential casting is a major objective and is carried out in order to achieve both a saving in costs and an increase in the rate of use of the plants. However, the service life of the nozzles of distribution tundishes is a limiting factor with respect to the required performance, and the failure of a nozzle during the sequence is detrimental to production outputs. In order to remedy this drawback "on line" replacement of the steel distribution tundishes is one solution; however, this operation is difficult in the case of plants having more than four casting lines and is accompanied by a deterioration of production outputs of the metal.